Quiet start to nuke summit

9:05 A.M. UPDATE: Dr. Gridlock reports that there are no delays, crowding or confusion on the Green Line despite Metro skipping the stop at Mount Vernon Square Station due to the Nuclear Security Summit. He says there are announcements being made about the change on platforms and on the train.

8:15 A.M. UPDATE: As of 8:15 p.m., traffic is moving freely on most of the streets entering the District. Traffic cameras show lighter than normal volume, and most of the usual congestion points are free of gridlock. Volume is building as the day progresses, but it appears to be well below usual levels. New York Avenue and even the 14th Street Bridge are relatively empty.

7:50 P.M. UPDATE: Some Metro trains were unusually uncrowded, including the Orange Line that runs from Eastern Market to McPherson Square. There were plenty of seats at 7 a.m. Another unusual sight for these commuters: Capitol Police in black bulletproof vests hanging out outside the entrance to the Starbucks next to Eastern Market.

-- Michelle Boorstein

7 A.M. UPDATE: So how is traffic this morning with portions of New York and Massachusetts avenues closed to traffic? It's not that bad. Drives in from points to the east on U.S. 50 were largely uneventful, with even the normal backups before Bladensburg Road not materializing.

Traffic cameras show light traffic on New York Avenue, and the streets around the security zone are free of problems. Of course, as heads of state arrive and motorcades fill the streets, we can expect issues to develop.

This blog will be updated throughout the summit, giving you real time traffic information and tips for navigating the next two days. Just remember that the while the traffic epicenter is going to be the summit, delays and headaches will ripple outward and impact commuters throughout the region. Add extra time to your commute and plan ahead. We'll do our best to help you stay as informed as possible.

I come into DC via North Capitol Street, and I think we got some of the traffic that normally uses other routes. More cars than I would expect on a Monday morning, and more zooming from one side to the other, one of the hallmarks of a driver unaccustomed to the route.

The only traffic I had was getting to Chain Bridge. Either VDot or DDot changed one of their traffic signals -- because now traffic going down N Glebe Rd onto chain bridge has to sit through half of its cycle not moving because the bridge is full of cars and there is no where to go. As soon as the cycle ends for N Glebe, traffic was Chain Bridge Road has it free sailing and fills up the bridge right as N Glebe gets its green again.